Common Potoo (Nyctibius griseus) - HBW 5, p. 300

Taxonomy:Caprimulgus griseus J. F. Gmelin, 1789, Cayenne. Forms superspecies with N. jamaicensis, and these two sometimes treated as conspecific, although voices differ greatly. Costa Rican birds, originally all included in single race, costaricensis, now thought to include two species; because costaricensis is currently recognized as a race of N. jamaicensis, birds of present species in Costa Rica and elsewhere in N are referred to adjacent race panamensis, although they possibly represent an unnamed taxon. Invalid race cornutus, recognized by some earlier authors, is now considered synonymous with nominate.. View all taxonomy...

Taxonomy: Caprimulgus griseus J. F. Gmelin, 1789, Cayenne. Forms superspecies with N. jamaicensis, and these two sometimes treated as conspecific, although voices differ greatly. Costa Rican birds, originally all included in single race, costaricensis, now thought to include two species; because costaricensis is currently recognized as a race of N. jamaicensis, birds of present species in Costa Rica and elsewhere in N are referred to adjacent race panamensis, although they possibly represent an unnamed taxon. Invalid race cornutus, recognized by some earlier authors, is now considered synonymous with nominate race, despite proposal for full species status based on geographically limited sample showing subtle differences in voice. Two subspecies currently accepted.